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Diffstat (limited to 'src/actors/scala/actors/threadpool/AbstractQueue.java')
| -rw-r--r-- | src/actors/scala/actors/threadpool/AbstractQueue.java | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/src/actors/scala/actors/threadpool/AbstractQueue.java b/src/actors/scala/actors/threadpool/AbstractQueue.java deleted file mode 100644 index 84ddc136bc..0000000000 --- a/src/actors/scala/actors/threadpool/AbstractQueue.java +++ /dev/null @@ -1,170 +0,0 @@ -/* - * Written by Doug Lea with assistance from members of JCP JSR-166 - * Expert Group and released to the public domain, as explained at - * http://creativecommons.org/licenses/publicdomain - */ - -package scala.actors.threadpool; - -import java.util.Iterator; -import java.util.Collection; -import java.util.NoSuchElementException; - -/** - * This class provides skeletal implementations of some {@link Queue} - * operations. The implementations in this class are appropriate when - * the base implementation does <em>not</em> allow <tt>null</tt> - * elements. Methods {@link #add add}, {@link #remove remove}, and - * {@link #element element} are based on {@link #offer offer}, {@link - * #poll poll}, and {@link #peek peek}, respectively but throw - * exceptions instead of indicating failure via <tt>false</tt> or - * <tt>null</tt> returns. - * - * <p> A <tt>Queue</tt> implementation that extends this class must - * minimally define a method {@link Queue#offer} which does not permit - * insertion of <tt>null</tt> elements, along with methods {@link - * Queue#peek}, {@link Queue#poll}, {@link Collection#size}, and a - * {@link Collection#iterator} supporting {@link - * Iterator#remove}. Typically, additional methods will be overridden - * as well. If these requirements cannot be met, consider instead - * subclassing {@link AbstractCollection}. - * - * <p>This class is a member of the - * <a href="{@docRoot}/../technotes/guides/collections/index.html"> - * Java Collections Framework</a>. - * - * @since 1.5 - * @author Doug Lea - */ -public abstract class AbstractQueue - extends AbstractCollection - implements Queue { - - /** - * Constructor for use by subclasses. - */ - protected AbstractQueue() { - } - - /** - * Inserts the specified element into this queue if it is possible to do so - * immediately without violating capacity restrictions, returning - * <tt>true</tt> upon success and throwing an <tt>IllegalStateException</tt> - * if no space is currently available. - * - * <p>This implementation returns <tt>true</tt> if <tt>offer</tt> succeeds, - * else throws an <tt>IllegalStateException</tt>. - * - * @param e the element to add - * @return <tt>true</tt> (as specified by {@link Collection#add}) - * @throws IllegalStateException if the element cannot be added at this - * time due to capacity restrictions - * @throws ClassCastException if the class of the specified element - * prevents it from being added to this queue - * @throws NullPointerException if the specified element is null and - * this queue does not permit null elements - * @throws IllegalArgumentException if some property of this element - * prevents it from being added to this queue - */ - public boolean add(Object e) { - if (offer(e)) - return true; - else - throw new IllegalStateException("Queue full"); - } - - /** - * Retrieves and removes the head of this queue. This method differs - * from {@link #poll poll} only in that it throws an exception if this - * queue is empty. - * - * <p>This implementation returns the result of <tt>poll</tt> - * unless the queue is empty. - * - * @return the head of this queue - * @throws NoSuchElementException if this queue is empty - */ - public Object remove() { - Object x = poll(); - if (x != null) - return x; - else - throw new NoSuchElementException(); - } - - - /** - * Retrieves, but does not remove, the head of this queue. This method - * differs from {@link #peek peek} only in that it throws an exception if - * this queue is empty. - * - * <p>This implementation returns the result of <tt>peek</tt> - * unless the queue is empty. - * - * @return the head of this queue - * @throws NoSuchElementException if this queue is empty - */ - public Object element() { - Object x = peek(); - if (x != null) - return x; - else - throw new NoSuchElementException(); - } - - /** - * Removes all of the elements from this queue. - * The queue will be empty after this call returns. - * - * <p>This implementation repeatedly invokes {@link #poll poll} until it - * returns <tt>null</tt>. - */ - public void clear() { - while (poll() != null) - ; - } - - /** - * Adds all of the elements in the specified collection to this - * queue. Attempts to addAll of a queue to itself result in - * <tt>IllegalArgumentException</tt>. Further, the behavior of - * this operation is undefined if the specified collection is - * modified while the operation is in progress. - * - * <p>This implementation iterates over the specified collection, - * and adds each element returned by the iterator to this - * queue, in turn. A runtime exception encountered while - * trying to add an element (including, in particular, a - * <tt>null</tt> element) may result in only some of the elements - * having been successfully added when the associated exception is - * thrown. - * - * @param c collection containing elements to be added to this queue - * @return <tt>true</tt> if this queue changed as a result of the call - * @throws ClassCastException if the class of an element of the specified - * collection prevents it from being added to this queue - * @throws NullPointerException if the specified collection contains a - * null element and this queue does not permit null elements, - * or if the specified collection is null - * @throws IllegalArgumentException if some property of an element of the - * specified collection prevents it from being added to this - * queue, or if the specified collection is this queue - * @throws IllegalStateException if not all the elements can be added at - * this time due to insertion restrictions - * @see #add(Object) - */ - public boolean addAll(Collection c) { - if (c == null) - throw new NullPointerException(); - if (c == this) - throw new IllegalArgumentException(); - boolean modified = false; - Iterator e = c.iterator(); - while (e.hasNext()) { - if (add(e.next())) - modified = true; - } - return modified; - } - -} |